MX record lookup
An MX (mail exchanger) record tells other mail servers where to deliver email for a domain. Enter a domain to see its MX records, their priorities, the hostnames they point to, and whether those hosts resolve to real addresses.
Runs the full report, including this check.
What the MX check covers
- Presence: at least one MX record, or a valid null-MX for a domain that does not receive mail.
- Priorities: lower numbers are preferred; the order is shown as returned by DNS.
- Resolution: each MX hostname is resolved to A and AAAA records, since an MX that does not resolve cannot receive mail.
- Provider: the mail provider is inferred from the MX hostnames.
Why MX records matter
Without a working MX record (or a fallback to the A record), inbound mail bounces. Mistyped hostnames, records pointing at decommissioned servers, and a missing null-MX on a send-only domain are common issues this check surfaces.
Frequently asked questions
What is a null-MX record?
A single MX record with priority 0 and a target of "." (RFC 7505). It explicitly states the domain receives no email, so senders fail fast instead of falling back to the A record. Recommended for send-only and parked domains.
What MX priority should I use?
Lower numbers are tried first. A single provider usually publishes several MX hosts with staggered priorities for redundancy. The exact numbers do not matter as long as the preferred host has the lowest value.